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Port the bug fix for PR 19704 (Missing dynamic relocation against undefined weak symbol) to the SPARC architecture.

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* elf32-sparc.c (elf_backend_fixup_symbol): New.
        * elf64-sparc.c (elf_backend_fixup_symbol): New.
        * elfxx-sparc.c (UNDEFINED_WEAK_RESOLVED_TO_ZERO): New.
        (_bfd_sparc_elf_link_hash_entry): Add has_got_reloc and
        has_non_got_reloc.
        (link_hash_newfunc): Initialize has_got_reloc and
	has_non_got_reloc.
        (_bfd_sparc_elf_size_dynamic_sections): Set interp to .interp
        section.
        (_bfd_sparc_elf_copy_indirect_symbol): Copy has_got_reloc and
        has_non_got_reloc.
        (_bfd_sparc_elf_check_relocs): Set has_got_reloc and
        has_non_got_reloc.
        (_bfd_sparc_elf_fixup_symbol): New function.
        (allocate_dynrelocs): Don't allocate space for dynamic
        relocations and discard relocations against resolved undefined
        weak symbols in executable.  Don't make resolved undefined weak
        symbols in executable dynamic.  Keep dynamic non-GOT/non-PLT
        relocation against undefined weak symbols in PIE.
        (_bfd_sparc_elf_relocate_section): Don't generate dynamic
        relocations against resolved undefined weak symbols in PIE
        (_bfd_sparc_elf_finish_dynamic_symbol): Keep PLT/GOT entries
        without ynamic PLT/GOT relocations for resolved undefined weak
        symbols.
        Don't generate dynamic relocation against resolved undefined
        weak symbol in executable.
        (pie_finish_undefweak_symbol): New function.
        (_bfd_sparc_elf_finish_dynamic_sections): Call
        pie_finish_undefweak_symbol on all symbols in PIE.
        * elfxx-sparc.h (_bfd_sparc_elf_link_hash_table): Add interp.
        (_bfd_sparc_elf_fixup_symbol): New function.
This commit is contained in:
Qing Zhao
2017-04-10 12:46:30 +01:00
committed by Nick Clifton
parent d236cfd444
commit bb1dd176fb
5 changed files with 228 additions and 28 deletions
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34
bfd/ChangeLog
View File

@@ -1,3 +1,37 @@
2017-04-10 Qing Zhao <qing.zhao@oracle.com>
* elf32-sparc.c (elf_backend_fixup_symbol): New.
* elf64-sparc.c (elf_backend_fixup_symbol): New.
* elfxx-sparc.c (UNDEFINED_WEAK_RESOLVED_TO_ZERO): New.
(_bfd_sparc_elf_link_hash_entry): Add has_got_reloc and
has_non_got_reloc.
(link_hash_newfunc): Initialize has_got_reloc and
has_non_got_reloc.
(_bfd_sparc_elf_size_dynamic_sections): Set interp to .interp
section.
(_bfd_sparc_elf_copy_indirect_symbol): Copy has_got_reloc and
has_non_got_reloc.
(_bfd_sparc_elf_check_relocs): Set has_got_reloc and
has_non_got_reloc.
(_bfd_sparc_elf_fixup_symbol): New function.
(allocate_dynrelocs): Don't allocate space for dynamic
relocations and discard relocations against resolved undefined
weak symbols in executable. Don't make resolved undefined weak
symbols in executable dynamic. Keep dynamic non-GOT/non-PLT
relocation against undefined weak symbols in PIE.
(_bfd_sparc_elf_relocate_section): Don't generate dynamic
relocations against resolved undefined weak symbols in PIE
(_bfd_sparc_elf_finish_dynamic_symbol): Keep PLT/GOT entries
without ynamic PLT/GOT relocations for resolved undefined weak
symbols.
Don't generate dynamic relocation against resolved undefined
weak symbol in executable.
(pie_finish_undefweak_symbol): New function.
(_bfd_sparc_elf_finish_dynamic_sections): Call
pie_finish_undefweak_symbol on all symbols in PIE.
* elfxx-sparc.h (_bfd_sparc_elf_link_hash_table): Add interp.
(_bfd_sparc_elf_fixup_symbol): New function.
2017-04-10 Nick Clifton <nickc@redhat.com>
* config.bfd: Remove ns32k from obsolete list.

1
bfd/elf32-sparc.c
View File

@@ -238,6 +238,7 @@ elf32_sparc_add_symbol_hook (bfd * abfd,
#define elf_backend_gc_sweep_hook _bfd_sparc_elf_gc_sweep_hook
#define elf_backend_plt_sym_val _bfd_sparc_elf_plt_sym_val
#define elf_backend_init_index_section _bfd_elf_init_1_index_section
#define elf_backend_fixup_symbol _bfd_sparc_elf_fixup_symbol
#define elf_backend_can_gc_sections 1
#define elf_backend_can_refcount 1

2
bfd/elf64-sparc.c
View File

@@ -904,6 +904,8 @@ const struct elf_size_info elf64_sparc_size_info =
_bfd_sparc_elf_finish_dynamic_symbol
#define elf_backend_finish_dynamic_sections \
_bfd_sparc_elf_finish_dynamic_sections
#define elf_backend_fixup_symbol \
_bfd_sparc_elf_fixup_symbol
#define bfd_elf64_mkobject \
_bfd_sparc_elf_mkobject

214
bfd/elfxx-sparc.c
View File

@@ -683,6 +683,20 @@ struct _bfd_sparc_elf_dyn_relocs
bfd_size_type pc_count;
};
/* Is an undefined weak symbol resolved to 0 ?
Reference to an undefined weak symbol is resolved to 0 when
building an executable if it isn't dynamic and
1. Has non-GOT/non-PLT relocations in text section.
Or
2. Has no GOT/PLT relocation. */
#define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
((EH)->elf.root.type == bfd_link_hash_undefweak \
&& bfd_link_executable (INFO) \
&& (_bfd_sparc_elf_hash_table (INFO)->interp == NULL \
|| !(EH)->has_got_reloc \
|| (EH)->has_non_got_reloc \
|| !(INFO)->dynamic_undefined_weak))
/* SPARC ELF linker hash entry. */
struct _bfd_sparc_elf_link_hash_entry
@@ -697,6 +711,13 @@ struct _bfd_sparc_elf_link_hash_entry
#define GOT_TLS_GD 2
#define GOT_TLS_IE 3
unsigned char tls_type;
/* Symbol has GOT or PLT relocations. */
unsigned int has_got_reloc : 1;
/* Symbol has non-GOT/non-PLT relocations in text sections. */
unsigned int has_non_got_reloc : 1;
};
#define _bfd_sparc_elf_hash_entry(ent) ((struct _bfd_sparc_elf_link_hash_entry *)(ent))
@@ -1018,6 +1039,8 @@ link_hash_newfunc (struct bfd_hash_entry *entry,
eh = (struct _bfd_sparc_elf_link_hash_entry *) entry;
eh->dyn_relocs = NULL;
eh->tls_type = GOT_UNKNOWN;
eh->has_got_reloc = 0;
eh->has_non_got_reloc = 0;
}
return entry;
@@ -1313,6 +1336,11 @@ _bfd_sparc_elf_copy_indirect_symbol (struct bfd_link_info *info,
edir->tls_type = eind->tls_type;
eind->tls_type = GOT_UNKNOWN;
}
/* Copy has_got_reloc and has_non_got_reloc. */
edir->has_got_reloc |= eind->has_got_reloc;
edir->has_non_got_reloc |= eind->has_non_got_reloc;
_bfd_elf_link_hash_copy_indirect (info, dir, ind);
}
@@ -1400,6 +1428,7 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
unsigned int r_type;
unsigned long r_symndx;
struct elf_link_hash_entry *h;
struct _bfd_sparc_elf_link_hash_entry *eh;
Elf_Internal_Sym *isym;
r_symndx = SPARC_ELF_R_SYMNDX (htab, rel->r_info);
@@ -1487,11 +1516,15 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
}
r_type = sparc_elf_tls_transition (info, abfd, r_type, h == NULL);
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
switch (r_type)
{
case R_SPARC_TLS_LDM_HI22:
case R_SPARC_TLS_LDM_LO10:
htab->tls_ldm_got.refcount += 1;
if (eh != NULL)
eh->has_got_reloc = 1;
break;
case R_SPARC_TLS_LE_HIX22:
@@ -1609,6 +1642,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
if (!_bfd_elf_create_got_section (htab->elf.dynobj, info))
return FALSE;
}
if (eh != NULL)
eh->has_got_reloc = 1;
break;
case R_SPARC_TLS_GD_CALL:
@@ -1677,6 +1713,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
goto r_sparc_plt32;
}
h->plt.refcount += 1;
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
eh->has_got_reloc = 1;
break;
case R_SPARC_PC10:
@@ -1730,6 +1769,9 @@ _bfd_sparc_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
if (h != NULL)
h->non_got_ref = 1;
if (eh != NULL && (sec->flags & SEC_CODE) != 0)
eh->has_non_got_reloc = 1;
r_sparc_plt32:
if (h != NULL && !bfd_link_pic (info))
{
@@ -2073,6 +2115,24 @@ _bfd_sparc_elf_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
return TRUE;
}
/* Remove undefined weak symbol from the dynamic symbol table if it
is resolved to 0. */
bfd_boolean
_bfd_sparc_elf_fixup_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *h)
{
if (h->dynindx != -1
&& UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
_bfd_sparc_elf_hash_entry (h)))
{
h->dynindx = -1;
_bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
h->dynstr_index);
}
return TRUE;
}
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
dynamic object, but we're not including those sections. We have to
@@ -2228,6 +2288,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
struct _bfd_sparc_elf_link_hash_table *htab;
struct _bfd_sparc_elf_link_hash_entry *eh;
struct _bfd_sparc_elf_dyn_relocs *p;
bfd_boolean resolved_to_zero;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
@@ -2236,6 +2297,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
htab = _bfd_sparc_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
if ((htab->elf.dynamic_sections_created
&& h->plt.refcount > 0)
|| (h->type == STT_GNU_IFUNC
@@ -2245,7 +2309,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
&& !h->forced_local
&& !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -2307,11 +2372,16 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* Make room for this entry. */
s->size += htab->plt_entry_size;
/* We also need to make an entry in the .rela.plt section. */
if (s == htab->elf.splt)
htab->elf.srelplt->size += SPARC_ELF_RELA_BYTES (htab);
else
htab->elf.irelplt->size += SPARC_ELF_RELA_BYTES (htab);
/* There should be no PLT relocations against resolved undefined
weak symbols in the executable. */
if (!resolved_to_zero)
{
/* We also need to make an entry in the .rela.plt section. */
if (s == htab->elf.splt)
htab->elf.srelplt->size += SPARC_ELF_RELA_BYTES (htab);
else
htab->elf.irelplt->size += SPARC_ELF_RELA_BYTES (htab);
}
if (htab->is_vxworks)
{
@@ -2351,7 +2421,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
&& !h->forced_local
&& !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -2366,22 +2437,25 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
dyn = htab->elf.dynamic_sections_created;
/* R_SPARC_TLS_IE_{HI22,LO10} needs one dynamic relocation,
R_SPARC_TLS_GD_{HI22,LO10} needs one if local symbol and two if
global. */
global. No dynamic relocations are needed against resolved
undefined weak symbols in an executable. */
if ((tls_type == GOT_TLS_GD && h->dynindx == -1)
|| tls_type == GOT_TLS_IE
|| h->type == STT_GNU_IFUNC)
htab->elf.srelgot->size += SPARC_ELF_RELA_BYTES (htab);
else if (tls_type == GOT_TLS_GD)
htab->elf.srelgot->size += 2 * SPARC_ELF_RELA_BYTES (htab);
else if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn,
bfd_link_pic (info),
h))
else if (((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
&& !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak)
&& WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn,
bfd_link_pic (info),
h))
htab->elf.srelgot->size += SPARC_ELF_RELA_BYTES (htab);
}
else
h->got.offset = (bfd_vma) -1;
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
if (eh->dyn_relocs == NULL)
return TRUE;
@@ -2422,12 +2496,44 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
}
/* Also discard relocs on undefined weak syms with non-default
visibility. */
visibility or in PIE. */
if (eh->dyn_relocs != NULL
&& h->root.type == bfd_link_hash_undefweak)
{
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
eh->dyn_relocs = NULL;
/* An undefined weak symbol is never
bound locally in a shared library. */
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
|| resolved_to_zero)
{
if (h->non_got_ref)
{
/* Keep dynamic non-GOT/non-PLT relocation so that we
can branch to 0 without PLT. */
struct _bfd_sparc_elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL;)
if (p->pc_count == 0)
*pp = p->next;
else
{
/* Remove other relocations. */
p->count = p->pc_count;
pp = &p->next;
}
if (eh->dyn_relocs != NULL)
{
/* Make sure undefined weak symbols are output
as dynamic symbols in PIEs for dynamic non-GOT
non-PLT reloations. */
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
}
else
eh->dyn_relocs = NULL;
}
/* Make sure undefined weak symbols are output as a dynamic
symbol in PIEs. */
@@ -2445,7 +2551,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
symbols which turn out to need copy relocs or are not
dynamic. */
if (!h->non_got_ref
if ((!h->non_got_ref
|| (h->root.type == bfd_link_hash_undefweak
&& !resolved_to_zero))
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
@@ -2455,7 +2563,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local)
&& !h->forced_local
&& !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@@ -2564,12 +2673,13 @@ _bfd_sparc_elf_size_dynamic_sections (bfd *output_bfd,
{
/* Set the contents of the .interp section to the interpreter. */
if (bfd_link_executable (info) && !info->nointerp)
{
s = bfd_get_linker_section (dynobj, ".interp");
BFD_ASSERT (s != NULL);
s->size = htab->dynamic_interpreter_size;
s->contents = (unsigned char *) htab->dynamic_interpreter;
}
{
s = bfd_get_linker_section (dynobj, ".interp");
BFD_ASSERT (s != NULL);
s->size = htab->dynamic_interpreter_size;
s->contents = (unsigned char *) htab->dynamic_interpreter;
htab->interp = s;
}
}
/* Set up .got offsets for local syms, and space for local dynamic
@@ -3007,12 +3117,14 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
reloc_howto_type *howto;
unsigned long r_symndx;
struct elf_link_hash_entry *h;
struct _bfd_sparc_elf_link_hash_entry *eh;
Elf_Internal_Sym *sym;
asection *sec;
bfd_vma relocation, off;
bfd_reloc_status_type r;
bfd_boolean is_plt = FALSE;
bfd_boolean unresolved_reloc;
bfd_boolean resolved_to_zero;
r_type = SPARC_ELF_R_TYPE (rel->r_info);
if (r_type == R_SPARC_GNU_VTINHERIT
@@ -3191,6 +3303,10 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
}
}
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
resolved_to_zero = (eh != NULL
&& UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
switch (r_type)
{
case R_SPARC_GOTDATA_OP_HIX22:
@@ -3419,10 +3535,14 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
|| is_vxworks_tls)
break;
/* Copy dynamic function pointer relocations. Don't generate
dynamic relocations against resolved undefined weak symbols
in PIE. */
if ((bfd_link_pic (info)
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
|| ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
&& !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak))
&& (! howto->pc_relative
|| !SYMBOL_CALLS_LOCAL (info, h)))
|| (!bfd_link_pic (info)
@@ -3431,7 +3551,8 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
&& !h->non_got_ref
&& ((h->def_dynamic
&& !h->def_regular)
|| h->root.type == bfd_link_hash_undefweak
|| (h->root.type == bfd_link_hash_undefweak
&& !resolved_to_zero)
|| h->root.type == bfd_link_hash_undefined)))
{
Elf_Internal_Rela outrel;
@@ -4352,11 +4473,20 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd,
{
struct _bfd_sparc_elf_link_hash_table *htab;
const struct elf_backend_data *bed;
struct _bfd_sparc_elf_link_hash_entry *eh;
bfd_boolean local_undefweak;
htab = _bfd_sparc_elf_hash_table (info);
BFD_ASSERT (htab != NULL);
bed = get_elf_backend_data (output_bfd);
eh = (struct _bfd_sparc_elf_link_hash_entry *) h;
/* We keep PLT/GOT entries without dynamic PLT/GOT relocations for
resolved undefined weak symbols in executable so that their
references have value 0 at run-time. */
local_undefweak = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
if (h->plt.offset != (bfd_vma) -1)
{
asection *splt;
@@ -4480,7 +4610,8 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd,
loc += rela_index * bed->s->sizeof_rela;
bed->s->swap_reloca_out (output_bfd, &rela, loc);
if (!h->def_regular)
if (!local_undefweak
&& !h->def_regular)
{
/* Mark the symbol as undefined, rather than as defined in
the .plt section. Leave the value alone. */
@@ -4494,9 +4625,12 @@ _bfd_sparc_elf_finish_dynamic_symbol (bfd *output_bfd,
}
}
/* Don't generate dynamic GOT relocation against undefined weak
symbol in executable. */
if (h->got.offset != (bfd_vma) -1
&& _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_GD
&& _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_IE)
&& _bfd_sparc_elf_hash_entry(h)->tls_type != GOT_TLS_IE
&& !local_undefweak)
{
asection *sgot;
asection *srela;
@@ -4787,6 +4921,25 @@ finish_local_dynamic_symbol (void **slot, void *inf)
h, NULL);
}
/* Finish up undefined weak symbol handling in PIE. Fill its PLT entry
here since undefined weak symbol may not be dynamic and may not be
called for _bfd_sparc_elf_finish_dynamic_symbol. */
static bfd_boolean
pie_finish_undefweak_symbol (struct bfd_hash_entry *bh,
void *inf)
{
struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh;
struct bfd_link_info *info = (struct bfd_link_info *) inf;
if (h->root.type != bfd_link_hash_undefweak
|| h->dynindx != -1)
return TRUE;
return _bfd_sparc_elf_finish_dynamic_symbol (info->output_bfd, info,
h, NULL);
}
bfd_boolean
_bfd_sparc_elf_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
{
@@ -4853,6 +5006,11 @@ _bfd_sparc_elf_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *i
/* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */
htab_traverse (htab->loc_hash_table, finish_local_dynamic_symbol, info);
/* Fill PLT entries for undefined weak symbols in PIE. */
if (bfd_link_pie (info))
bfd_hash_traverse (&info->hash->table,
pie_finish_undefweak_symbol,
info);
return TRUE;
}

5
bfd/elfxx-sparc.h
View File

@@ -46,6 +46,9 @@ struct _bfd_sparc_elf_link_hash_table
{
struct elf_link_hash_table elf;
/* Short-cut to get to dynamic linker sections. */
asection *interp;
union
{
bfd_signed_vma refcount;
@@ -136,6 +139,8 @@ extern bfd_boolean _bfd_sparc_elf_finish_dynamic_symbol
Elf_Internal_Sym *sym);
extern bfd_boolean _bfd_sparc_elf_finish_dynamic_sections
(bfd *, struct bfd_link_info *);
extern bfd_boolean _bfd_sparc_elf_fixup_symbol
(struct bfd_link_info *, struct elf_link_hash_entry *);
extern bfd_boolean _bfd_sparc_elf_object_p
(bfd *);
extern bfd_vma _bfd_sparc_elf_plt_sym_val